josh that was exactly my original question. See the third post on this page, for more detail.
Also, i don’t understand your post. So you do think that the tallis katan worn by the majority of frum jews, in between their shirts and their undershirts, has a function?
Or perhaps you aren’t familiar with this kind of tallis katan at all, and the kind that you wear also serves as an undershirt (which i still don’t know if it would be considered a ‘ksus yoim’ according to the second defintion set out above, and i am inclined to think not) which led you to ask your question.
Also, Haleivi, what is the purpose that our tallis katan beged serves (aside to make one sweaty and uncomfortable in many cases)?